Subscription callbacks for acl and interface app modules (sonic-net#86)

* Subscription callbacks for acl and interface app modules

* Implemented translateSubscribe() and processSubscribe() methods in
  AclApp and IntfApp. Mapping is based on the existing processGet()
  implementation. This may not be accurate since both the app modules
  have not been updated since long time. But it will be useful for
  testing the subscription feature.

* Current IntfApp supports only physcial ports in get/set operations.
  Same limitation is applicable for subscription as well.

* Added utilities for processing the path objects and help prepare
  the translateSubscribe() resposne.

* Added gotest helper functions to call translateSubscribe() and
  verify the responses. Added gotest cases to verify different
  openconfig-acl and openconfig-interfaces yang paths.

* Fixed incorrect paths & payloads used by the existing AclApp get/set
  test cases.

Signed-off-by: Sachin Holla <sachin.holla@broadcom.com>

* Init test data for ACL gotests

* Minor cleanups to address review comments

* Define constants for port related table names

---------

Signed-off-by: Sachin Holla <sachin.holla@broadcom.com>

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/godbus/dbus/v5 v5.1.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
+	github.com/kylelemons/godebug v1.1.0
 	github.com/openconfig/gnmi v0.0.0-20200617225440-d2b4e6a45802
 	github.com/openconfig/goyang v0.0.0-20200309174518-a00bece872fc
 	github.com/openconfig/ygot v0.7.1

translib/acl_app.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/Azure/sonic-mgmt-common/translib/db"
 	"github.com/Azure/sonic-mgmt-common/translib/ocbinds"
+	"github.com/Azure/sonic-mgmt-common/translib/path"
 	"github.com/Azure/sonic-mgmt-common/translib/tlerr"
 
 	log "github.com/golang/glog"
@@ -1215,6 +1216,7 @@ func convertOCToInternalIPv4(ruleData db.Value, aclName string, ruleIndex uint32
 	if rule.Ipv4.Config.DestinationAddress != nil {
 		ruleData.Field["DST_IP"] = *rule.Ipv4.Config.DestinationAddress
 	}
+	ruleData.Field["IP_TYPE"] = "IPV4ANY"
 }
 
 func convertOCToInternalIPv6(ruleData db.Value, aclName string, ruleIndex uint32, rule *ocbinds.OpenconfigAcl_Acl_AclSets_AclSet_AclEntries_AclEntry) {
@@ -1246,6 +1248,7 @@ func convertOCToInternalIPv6(ruleData db.Value, aclName string, ruleIndex uint32
 	if rule.Ipv6.Config.DestinationFlowLabel != nil {
 		ruleData.Field["DST_FLOWLABEL"] = strconv.FormatInt(int64(*rule.Ipv6.Config.DestinationFlowLabel), 10)
 	}
+	ruleData.Field["IP_TYPE"] = "IPV6ANY"
 }
 
 func convertOCToInternalTransport(ruleData db.Value, aclName string, ruleIndex uint32, rule *ocbinds.OpenconfigAcl_Acl_AclSets_AclSet_AclEntries_AclEntry) {
@@ -1620,6 +1623,19 @@ func getAclTypeOCEnumFromName(val string) (ocbinds.E_OpenconfigAcl_ACL_TYPE, err
 	}
 }
 
+func convertSonicAclTypeToOC(aclType string) (ocbinds.E_OpenconfigAcl_ACL_TYPE, string) {
+	switch aclType {
+	case SONIC_ACL_TYPE_IPV4:
+		return ocbinds.OpenconfigAcl_ACL_TYPE_ACL_IPV4, "ACL_IPV4"
+	case SONIC_ACL_TYPE_IPV6:
+		return ocbinds.OpenconfigAcl_ACL_TYPE_ACL_IPV6, "ACL_IPV6"
+	case SONIC_ACL_TYPE_L2:
+		return ocbinds.OpenconfigAcl_ACL_TYPE_ACL_L2, "ACL_L2"
+	default:
+		return ocbinds.OpenconfigAcl_ACL_TYPE_UNSET, ""
+	}
+}
+
 func getAclKeyStrFromOCKey(aclname string, acltype ocbinds.E_OpenconfigAcl_ACL_TYPE) string {
 	aclN := strings.Replace(strings.Replace(aclname, " ", "_", -1), "-", "_", -1)
 	aclT := acltype.ΛMap()["E_OpenconfigAcl_ACL_TYPE"][int64(acltype)].Name
@@ -1636,9 +1652,136 @@ func isSubtreeRequest(targetUriPath string, nodePath string) bool {
 }
 
 func (app *AclApp) translateSubscribe(req translateSubRequest) (translateSubResponse, error) {
-	return emptySubscribeResponse(req.path)
+	ymap := yangMapTree{
+		subtree: map[string]*yangMapTree{
+			"acl-sets/acl-set": {
+				mapFunc: app.translateSubscribeAclSet,
+				subtree: map[string]*yangMapTree{
+					"acl-entries/acl-entry": {
+						mapFunc: app.translateSubscribeAclEntry,
+					},
+				},
+			},
+			"interfaces": {
+				mapFunc: app.translateSubscribeAclBindings,
+			},
+		}}
+
+	nb := notificationInfoBuilder{
+		pathInfo: NewPathInfo(req.path),
+		yangMap:  ymap,
+	}
+	return nb.Build()
+}
+
+func (app *AclApp) translateSubscribeAclSet(nb *notificationInfoBuilder) error {
+	aclName := nb.pathInfo.StringVar("name", "*")
+	aclType := nb.pathInfo.StringVar("type", "*")
+
+	nb.New().PathKey("name", aclName).PathKey("type", aclType)
+	nb.Table(db.ConfigDB, ACL_TABLE).Key(aclName + "_" + aclType)
+	if nb.SetFieldPrefix("config") {
+		nb.Field("description", ACL_DESCRIPTION)
+	}
+	if nb.SetFieldPrefix("state") {
+		nb.Field("description", ACL_DESCRIPTION)
+	}
+
+	return nil
+}
+
+func (app *AclApp) translateSubscribeAclEntry(nb *notificationInfoBuilder) error {
+	aclName := nb.pathInfo.StringVar("name", "*")
+	aclType := nb.pathInfo.StringVar("type", "*")
+	ruleSeq := nb.pathInfo.StringVar("sequence-id", "*")
+
+	nb.New().PathKey("sequence-id", ruleSeq)
+	nb.Table(db.ConfigDB, RULE_TABLE).Key(aclName+"_"+aclType, "RULE_"+ruleSeq)
+
+	ipAclFieldSetter := func(prefix string) {
+		if nb.SetFieldPrefix(prefix) {
+			nb.Field("source-address", "SRC_IP")
+			nb.Field("destination-address", "DST_IP")
+			nb.Field("dscp", "DSCP")
+			nb.Field("protocol", "IP_PROTOCOL")
+		}
+	}
+	ipv6AclFieldSetter := func(prefix string) {
+		if nb.SetFieldPrefix(prefix) {
+			nb.Field("source-address", "SRC_IPV6")
+			nb.Field("destination-address", "DST_IPV6")
+			nb.Field("dscp", "DSCP")
+			nb.Field("protocol", "IP_PROTOCOL")
+		}
+	}
+	ipTransportFieldSetter := func(prefix string) {
+		if nb.SetFieldPrefix(prefix) {
+			nb.Field("source-port", "L4_SRC_PORT")
+			nb.Field("source-port", "L4_SRC_PORT_RANGE")
+			nb.Field("destination-port", "L4_DST_PORT")
+			nb.Field("destination-port", "L4_DST_PORT_RANGE")
+			nb.Field("tcp-flags", "TCP_FLAGS")
+		}
+	}
+	if wildcardMatch(aclType, "ACL_IPV4") {
+		ipAclFieldSetter("ipv4/config")
+		ipAclFieldSetter("ipv4/state")
+		ipTransportFieldSetter("transport/config")
+		ipTransportFieldSetter("transport/state")
+	}
+	if wildcardMatch(aclType, "ACL_IPV6") {
+		ipv6AclFieldSetter("ipv6/config")
+		ipv6AclFieldSetter("ipv6/state")
+		ipTransportFieldSetter("transport/config")
+		ipTransportFieldSetter("transport/state")
+	}
+	if nb.SetFieldPrefix("actions/config") {
+		nb.Field("forwarding-action", "PACKET_ACTION")
+	}
+	if nb.SetFieldPrefix("actions/state") {
+		nb.Field("forwarding-action", "PACKET_ACTION")
+	}
+
+	return nil
+}
+
+func (app *AclApp) translateSubscribeAclBindings(nb *notificationInfoBuilder) error {
+	nb.New().OnChange(false).Preferred(Sample)
+	return nil
 }
 
 func (app *AclApp) processSubscribe(req processSubRequest) (processSubResponse, error) {
-	return processSubResponse{}, tlerr.New("not implemented")
+	resp := processSubResponse{
+		path: req.path,
+	}
+
+	switch req.table.Name {
+	case ACL_TABLE:
+		if path.GetElemAt(resp.path, 2) != "acl-set" {
+			return resp, tlerr.New("Unknown path template: %v", path.String(req.path))
+		}
+
+		_, aclTypeStr := convertSonicAclTypeToOC(req.entry.Get(ACL_TYPE))
+		aclName := strings.TrimSuffix(req.key.Get(0), "_"+aclTypeStr)
+		path.SetKeyAt(resp.path, 2, "name", aclName)
+		path.SetKeyAt(resp.path, 2, "type", aclTypeStr)
+
+	case RULE_TABLE:
+		aclName := req.key.Get(0)
+		aclEntry, err := req.dbs[db.ConfigDB].GetEntry(&db.TableSpec{Name: ACL_TABLE}, asKey(aclName))
+		if err != nil {
+			return resp, err
+		}
+
+		_, aclTypeStr := convertSonicAclTypeToOC(aclEntry.Get(ACL_TYPE))
+		aclName = strings.TrimSuffix(aclName, "_"+aclTypeStr)
+		path.SetKeyAt(resp.path, 2, "name", aclName)
+		path.SetKeyAt(resp.path, 2, "type", aclTypeStr)
+		path.SetKeyAt(resp.path, 4, "sequence-id", strings.TrimPrefix(req.key.Get(1), "RULE_"))
+
+	default:
+		return resp, tlerr.New("Unknown table: %s", req.table.Name)
+	}
+
+	return resp, nil
 }